Comparative efficacy of Malathion and spinosad bait sprays against Ceratitis capitata Wiedmann (Diptera: Tephritidae) in Tunisian citrus orchards

Malathion is the key insecticide used in the control of the Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) in Tunisia. Resistance to this organophosphate insecticide has been reported in various insect species. The use of Malathion will slowly phase out and replaced by more environment friendly insecticides such as spinosad. In this study, we evaluated spinosad as a replacement of Malathion in bait spray to control C. capitata in Tunisian citrus orchards. The assessment was based on weekly monitoring of C. capitata males catches in traps baited with trimedlure and the estimate of fruit damage on the Maltaise variety. Our results showed that the population level was significantly lower in spinosad than in Malathion bait sprays with 1.6 and 15.30 fly/trap/day respectively. The effectiveness of spinosad treatment was confirmed by significantly low rates of fruit damage not exceeding 9.75 %.